Cross posting to see how I can get help needed to make this "condom" to make water-resistant

carlos_berdeal

https://cad.onshape.com/documents/b97bb9224054235f4741a979/w/7a10ff4e8009a9952f6e9b3f/e/4efa7b9825819f792413c7eb

So I am working with a file that I created from a 3d scan. It is a remote control of sorts. I am trying to create a silicone "condom" to water-resist the bottom connection. Like this: https://imgur.com/a/GzVJNwM

But I need to make the cavity either by adding some material to the outside of the remote or by removing material from the potential mold. It needs to be "form fitting" as there are no Flat surfaces on this remote. Problem is the scan shows up as surface pieces. After processing the 3d scan from triangles to .obj(quad) then converting in Fusion 360 to T-splines then converting to brep file. Now I am lost as to how to get it into a solid so I do not have all these surface parts. Any help in this sub would be great. Will post in Fusion as well. Sorry if I am posting in the wrong sub but I just know someone around here might have a tid-bit of info. Thank you for any help!

Matt_Shields

Not sure exactly what you're trying to do, but Onshape definitely allows for mixed modeling.  If you're trying to increase the size of the cavity, try using the Offset option on your boolean subtract.  It probably won't work for the tiny faces at the bottom, but it will get you a long way.

Evan_Reese

Here's an example workflow. It's not complete, but should get you going. It still needs alignment pins, gates, and vents for the mold, but you can model those in however you want. Also, I'd substitute my first steps for your 3D scan. I just needed to make a quick part to work with. Note, this assumes it will be stretchy enough to come off of the mold core even thought it's tapered the "wrong" way. If you have access to compressed air, that's a handy way to de-mold it.

Evan_Reese

of course, you could probably get away with just dipping the product in rubber and skipping all of this, but it would be uglier, haha.

carlos_berdeal

@Evan_Reese Fire my man!!!
Valid points I will take note! This is awesome. How did you get to those solid drawings? Is it just textures or file formats? I am on a mission to learn this my friend! This is what I am trying to learn. Evan, You killed it!!!!!

carlos_berdeal

Main goal is to create a seal between the USB-C cable and salt water to the ultrasoundtransducer. The device is waterproof but it is wireless as well, Wireless does not work underwater, I need to create a temporary barrier between the USB-C cable and the sea-water making a mold to seal that end. Thank you for your idea

carlos_berdeal

@Evan_Reese Main goal is to create a seal between the USB-C cable and salt water to the ultrasound transducer. The device is waterproof but it is wireless as well, Wireless does not work underwater, I need to create a temporary barrier between the USB-C cable and the sea-water making a mold to seal that end. Thank you for your idea.

carlos_berdeal

@Evan_Reese funny thing is this project started by "painting" on the silicone to the remote and the USB cable. What a mess! The Idea is to try to get a solid mold to be able to design the sleeve for the USB cable and prevent it from getting saltwater to the usb connection as it is a live connection for imaging and will be tested in the ocean.

carlos_berdeal

@Matt_Shields Thank you. Do you know if there is a way to join all the faces to make a solid?

Evan_Reese

Ooh, interesting use case. If you're diving any depth with it, you're going to be battling some serious hydrostatic pressure, so I might recommend a more thoughtful seal area, which could look something like an o-ring like area inside the sleeve near the top opening, and even possibly a place to clamp the seal with a zip tie or hose clamp.

Matt_Shields

I played around with Thicken, Enclose, and Offset surface, but they all run into problems down at the bottom at the USB port.

Evan_Reese

The topology of the surfaces from the scan seem like a problem. I recommend emulating my lofts in the example document I did to model the outside of the silicone shape, then you can use the scan to cut out the inner portion to skirt around the issues you'll have offsetting that messy scan geometry. Another option is to model a clean version of the product using the scan as a reference, and go from there.